The theoretical and experimental investigations presented in this thesis are primarily related to the dynamic response of inelastic multi-storey building frames subjected to strong ground motions. The main purpose is to investigate, both analytically and experimentally, those aspects of the dynamic response characteristics which are of importance in aseismic design. In the first part of the thesis, the various parameters pertaining to the structural system are varied in a systematic manner and an assessment is made of the influence of this variation on the maximum response characteristics of the dynamic system. The second part of the thesis consists of an experimental investigation into the inelastic dynamic response of multi-storey frames. The comparison of experimentally obtained inelastic response and that predicted theoretically indicated a good agreement between the two. / Thesis / Doctor of Philosophy (PhD)

Seismic hazard calculations for sites in eastern North America have traditionally assumed a Poisson process to describe the temporal behavior of earthquakes and have employed the Gutenberg-Richter relationship to define the frequency distribution of earthquake magnitude. For sites in areas where geological information indicates recurrent, large earthquakes, however, such data imply a rate for large events which often exceeds that predicted by the Gutenberg-Richter relationship. One way in which this discrepancy can be reconciled is to assume that the larger events occur as a time-dependent, or renewal, process and possess a "characteristic earthquake" magnitude distribution. The main purpose of this study is to make a quantitative comparison of seismic hazard estimates for Charleston of the influences of 1) the Poisson temporal model assuming the Gutenberg-Richter and characteristic earthquake magnitude recurrence relationships with 2) the renewal temporal model assuming the characteristic magnitude recurrence relationship. Other issues that are examined are the sensitivity of uncertainties of hazard model parameters such as maximum magnitude and seismic source delineation. Probabilistic seismic hazard calculations for the next 50 years were performed at Charleston for all potential seismic sources. The highest estimate of seismic hazard was obtained with the Poisson temporal model and characteristic earthquake recurrence relationship. The lowest hazard was obtained with the renewal temporal model and characteristic magnitude recurrence relationship. The results of this study are in good agreement with hazard estimates for Charleston in the most recent national seismic hazard maps. / Master of Science

Since 1976, the General Directorate of Disaster Affairs of Turkey has deployed several strong-motion accelerographs at selected sites. Within the framework of the project entitled Compilation of National Strong Ground Motion Database in Accordance with International Standards, initiated in 2006, site conditions at a total of 153 strong-motion sites were investigated within the uppermost 30 m depth through boreholes including Standard Penetration Testing and surface seismics by means of Multi-channel Analysis of Surface Waves (MASW). In this study, firstly, the assessment of the site characterization was held by making use NEHRP Provisions, EC-8 and Turkish Seismic Design Code. The corrected penetration resistances are calculated and observed how it affects the classification. In addition, the consistency of site classes obtained from either penetration resistance or shear wave velocity criteria is examined. Also the consistency of the boundaries of the site classes in terms of shear wave velocity and penetration resistance data pairs are investigated. Secondly, the liquefaction potential of these sites is examined. Thirdly and finally, the shear wave velocity profiles obtained from MASW technique are contrasted to other seismic tests.

Assessment of potential ground motions in seismically active regions is essential for purposes of seismic design and analysis. Peak ground motion intensity values and frequency content of seismic excitations are required for reliable seismic design, analysis and retrofitting of structures. In regions of sparse or no strong ground motion records, ground motion simulations provide physics-based synthetic records. These simulations provide not only the earthquake engineering parameters but also give insight into the mechanisms of the earthquakes. This thesis presents strong ground motion simulations in three regions of intense seismic activity. Stochastic finite-fault simulation methodology with a dynamic corner frequency approach is applied to three case studies performed in D&uuml / zce, L&rsquo / Aquila and Erzincan regions. In D&uuml / zce study, regional seismic source, propagation and site parameters are determined through validation of the simulations against the records. In L&rsquo / Aquila case study, in addition to study of the regional parameters, the limitations of the method in terms of simulating the directivity effects are also investigated. In Erzincan case study, where there are very few records, the optimum model parameters are determined using a large set of simulations with an error-minimization scheme. Later, a parametric sensitivity study is performed to observe the variations in simulation results to small perturbations in input parameters. Results of this study confirm that stochastic finite-fault simulation method is an effective technique for generating realistic physics-based synthetic records of large earthquakes in near field regions.

Ground-motion data processing is a necessity for most earthquake engineering related studies. Important engineering parameters such as the peak values of ground motion and the ordinates of the response spectra are determined from the strong ground-motion data recorded by accelerometers. However, the raw data needs to be processed since the recorded data always contains high- and low-frequency noise from different sources. Low-cut filters are the most popular ground-motion data processing scheme for removing long-period noise. Removing long-period noise from the raw accelogram is important since the displacement spectrum that provides primary information about deformation demands on structural systems is highly sensitive to the long-period noise. The objective of this study is to investigate the effect of low-cut filtering period on linear and nonlinear deformation demands. A large number of strong ground motions from Europe and the Middle East representing different site classes as well as different magnitude and distance ranges are used to conduct statistical analysis. The statistical results are used to investigate the influence of low-cut filter period on spectral displacements. The results of the study are believed to be useful for future generation ground-motion prediction equations on deformation demands that are of great importance in performance-based earthquake engineering.

Prior to this study, to our best knowledge, no cast-in-place, older-type RC building has ever been subjected to near-field strong ground motions from three major earthquakes. This happened in an indirect way in Turkey over a time span of eleven years. Three identical buildings belonging to Ministry of Public Works and Resettlement (MPWR) that had been built to the same design templates, experienced March 13th 1992 Erzincan earthquake in Erzincan, November 12th 1999 D&uuml / zce earthquake in Bolu and May 1st 2003 Bing&ouml / l earthquake in Bing&ouml / l, respectively. The ground motion sensor stations were fortuitously nearby in an adjacent single-story building in Bolu and Bing&ouml / l. The station in Erzincan was in a single-story building about 2 km away from the case study building but we assume that the record applies to the building there. These three data represent characteristics of near-field ground motions and the distance of the sensor stations to the nearest fault trace was less than 10 km. The buildings sustained varying degrees of damage during the earthquakes and their damage survey was employed through site investigations. Given that the damage information, input motions, design drawings and material properties of the buildings are all known, this provided an opportunity to predict the structural damage to these buildings by proper modeling using the tools of current computational performance assessment procedures. In this circumstance, three dimensional (3D) analytical models of the MPWR buildings have been performed. Bi-directional excitations have been applied to the models by nonlinear time history analyses (NTHA). The results illustrate that NTHA are capable of indicating the occurrence of shear failure in captive columns / however, they overestimate the global damage level for all buildings. The overestimation is more significant in Erzincan case where the building sustained a pulse-type motion without significant distress.

This thesis addresses two fundamental topics in Engineering Seismology; the application of Probabilistic Seismic Hazard Analysis (PSHA) methodology, and the estimation of measures of Strong Ground Motion. These two topics, while being related, are presented as separate sections. In the first section, state-of-the-art PSHA methodologies are applied to various sites in the Buller Region, South Island, New Zealand. These sites are deemed critical to the maintenance of economic stability in the region. A fault-source based seismicity model is developed for the region that is consistent with the governing tectonic loading, and seismic moment release of the region. In attempting to ensure this consistency the apparent anomaly between the rates of activity dictated by deformation throughout the Quaternary, and rates of activity dictated by observed seismicity is addressed. Individual fault source activity is determined following the application of a Bayesian Inference procedure in which observed earthquake events are attributed to causative faults in the study region. The activity of fault sources, in general, is assumed to be governed by bounded power law behaviour. An exception is made for the Alpine Fault which is modelled as a purely characteristic source. The calculation of rates of exceedance of various ground motion indices is made using a combination of Poissonian and time-dependent earthquake occurrence models. The various ground motion indices for which rates of exceedance are determined include peak ground acceleration, ordinates of 5% damped Spectral Acceleration, and Arias Intensity. The total hazard determined for each of these ground motion measures is decomposed using a four dimensional disaggregation procedure. From this disaggregation procedure, design earthquake scenarios are specified for the sites that are considered. The second part of the thesis is concerned with the estimation of ground motion measures that are more informative than the existing scalar measures that are available for use in New Zealand. Models are developed for the prediction of Fourier Amplitude Spectra (FAS) as well as Arias Intensity for use in the New Zealand environment. The FAS model can be used to generate ground motion time histories for use in structural and geotechnical analyses. Arias Intensity has been shown to be an important strong motion measure due to its positive correlation with damage in short period structures as well as its utility in predicting the onset of liquefaction and landslides. The models are based upon the analysis of a dataset of New Zealand Strong Motion records as well as supplementary near field records from major overseas events. While the two measures of ground motion intensity are strongly related, different methods have been adopted in order to develop the models. As part of the methodology used for the FAS model, Monte Carlo simulation coupled with a simple ray tracing procedure is employed to estimate source spectra from various New Zealand earthquakes and, consequently, a magnitude - corner-frequency relationship is obtained. In general, the parameters of the predictive equations are determined using the most state-of-the-art mixed effects regression procedures.

No description available.